Surface Finishing of Needles for High-performance Biopsy

Realizing simultaneous internal and external surface finishing of the needle should result in significant processing time reduction. This paper clarifies the magnetic field and magnetic particle distribution specifically required to achieve the simultaneous surface finishing of 18 gauge 316 stainless steel needles, and the efficacy of the resulting simultaneous surface finishing is described. Both the inner and external surfaces of needles, 0.4–0.5 μm Sa, can be simultaneously finished to around 0.01 μm Sa in 5 min.